<style>
.container{ float:left;
position:relative;
left:50%}
.container ul{
...
position:relative;
left:-50%;}
.container li{ float:left;display:inline; ...}
</style><body> <div class="container"> <ul> <li>...</li> </ul> </div> </body>
父元素.container已经设置了left: 50%,为什么子元素ul,li设置left: -50%还要加上父元素.container?
Caballarii